1. Technical Field
The present invention relates to a liquid crystal device having a lighting device and a liquid crystal panel, an electronic apparatus having the liquid crystal device, and the corresponding lighting device.
2. Related Art
Among various liquid crystal devices, a liquid crystal device having a transparent or translucent liquid crystal panel includes a lighting device, which is called a so-called backlight device, and a liquid crystal panel disposed to overlap the side of a light emitting surface of the lighting device, and modulates the illuminating light emitted from the lighting device by a liquid crystal panel to display an image. Therefore, regarding the lighting device, it is required to make the distribution of emission intensity of the illuminating light uniform.
Here, regarding the lighting device having the light emitting element at the end portion of a light guide plate, it is proposed that a plurality of light emitting elements are provided along two sides facing each other in the first direction of the light guide plate, and the location of the light emitting element disposed along one side and the location of the light emitting element disposed along the other side are shifted in the second direction (see JP-A-2006-120361).
In addition, there is proposed that, since light is excessively dispersed at an integrated light guide plate when the emission intensity of illuminating light emitted from the lighting device is controlled at every region, for example, as shown in FIG. 10A, a plurality of rectangular light guide plate portions 81X extending in the first direction are arranged in parallel in the second direction which is a direction of the short side, and a light emitting element 89 is disposed at the end portion (a light incident portion 88X) of the light guide plate portion 81X in the first direction (see JP-A-2009-163902).
Meanwhile, as shown in FIG. 10B, there is proposed a lighting device in which, even though the emission intensity of illuminating light is not controlled for every region, a plurality of trapezoidal light guide plate portions 82Y having two sides with different lengths facing each other in the first direction are arranged in the second direction which faces the first direction, and the light emitting element 89 is disposed at the end surface (a light incident portion 88Y) located at the long side of a light guide plate portion 82Y (see JP-A-2006-108045).
However, in the case of the lighting device disclosed in JP-A-2009-163902, the size of the light incident portion 88X of the light guide plate portion 81X in the second direction is great in comparison to the size of the light emitting element 89 in the second direction. For this reason, when illuminating light is emitted from the light guide plate portion 81X, near the light incident portion 88X of the light guide plate portion 81X, the emission intensity of the illuminating light from the portion facing the light emitting element 89 is great, but at a position deviated from the corresponding region in the second direction, the emission intensity of the illuminating light may be easily lowered. In addition, in the case of adopting the configuration disclosed in JP-A-2006-108045, since the size of the light incident portion 88Y of the light guide plate portion 82Y in the second direction is great in comparison to the size of the light emitting element 89 in the second direction, further to the lighting device disclosed in JP-A-2009-163902, and so the above problem is remarkable.
Therefore, in the case of adopting the configurations disclosed in JPA-2009-163902 and JP-A-2006-108045, it is required to decrease the dimension of the light guide plate portions 81X and 82Y in the second direction, increase the number of the light guide plate portions 81X and 82Y and the light emitting elements 89, and design the size of the light guide plate portions 81X and 82Y in the second direction close to the size of the light emitting element 89 in the second direction, however, in the corresponding configuration, the cost of the lighting device or the liquid crystal device increases. In addition, in the configurations disclosed in JP-A-2009-163902 and JP-A-2006-108045, decreasing the difference in emission intensity of illuminating light near the light incident portions 88X and 88Y of the light guide plate portions 81X and 82Y by providing the light emitting element 89 at a position greatly spaced from the light incident portions 88X and 88Y of the light guide plate portions 81X and 82Y may be considered, but in the corresponding configuration, the dimension of the lighting device in the first direction becomes great, and so there is a problem that it cannot be mounted to a liquid crystal device.